An inkjet recording method that is a typical method among various types of color recording methods is a method of producing small droplets of ink according to a recording signal and of attaching them to a record-receiving material to perform recording. In recent years, an inkjet technology has progressed so as to be expected to be developed to digital commercial printing, and even in the field of high-definition printing, which has been performed heretofore by silver halide photography and offset printing, the inkjet recording method has started to be employed.
In an inkjet recording method using a water-based ink, not only a record receiving material which has an ink receiving layer such as inkjet paper or ink jet glossy paper but also a record receiving material whose ink absorption capacity is low and which does not have an ink receiving layer such as general-purpose plain paper is used as a record-receiving material.
Among them, with the record-receiving material which does not have an ink receiving layer, since it is difficult for ink to penetrate, particularly when a water-based pigment ink is used, a phenomenon such as bleeding (bleed) between colors or low uniformity (mottling) of an image obtained may occur. Since recording is often performed on the record-receiving material which does not have an ink receiving layer, suppression of these phenomena is considered to be one of important problems.
In order to address the problem described above, an attempt is made to and a surfactant, a penetrating agent or a polymer into an ink to suppress the phenomena.
Patent Document 1 discloses an ink to which an anionic or nonionic surfactant and alkane diol such as 1,2-hexane diol are added and in which high-quality image without mottling and bleed can thus be realized.
Patent Document 2 discloses an ink set to which a water-soluble compound having a predetermined coefficient of hydrophilicity-hydrophobicity is added to enhance quick drying and reduce bleed.
Patent Documents 3 and 4 disclose an ink set to which a polymer is added to reduce a bleed phenomenon.
Patent Document 1: Japanese Unexamined Patent Application, Publication No. 2003-213179
Patent Document 2: Japanese Unexamined Patent Application, Publication No. 2013-86379
Patent Document 3: Japanese Unexamined Patent Application, Publication No. 2012-1674
Patent Document 4: Japanese Unexamined Patent Application, Publication No. 2012-188467